I had 8 GTX 1070s and 8 GTX 1060 3GB mining on windows using MSI afterburner to OC. It works, but dear god sometimes rig would run for 1-3 days, then just auto restart other 1060 3GB rig would just constantly crash and crash run for a 1-2 days then crash. Windows and 8 GPU Mining do not mix. I think 6 would be the best if you doing small rig. IMHO just like everyone said, if your doing more cards get Linux. I highly recommend Simplemining OS(SMOS) super easy setup for Nvidia/RX cards. Their is a 2 dollar a month rig fee ($24 a year for one rig).
I will praise it highly it got both rigs running stable at HIGHER memory overclocks and you have full control of wattage used! I have the 1060 3GB running 80w per card for a total of 740w ~ for the whole rig! 140mh/s 3.5gh/s DCR
Maybe ill give SMOS a try then, i can see that all cards are attached/installed, but once i start mining it all crashes when above 8 Nvidia`s..